Signum Pro polyester
Signum Pro Firestorm
Round co-polyester monofilament
Data verified January 2025
$9-12 Per Set
16, 17, 18 Gauges
medium high Stiffness
13+ Min Age
Junior Player Guide
For Parents Arm Friendliness Low
Cost Effectiveness Great value
Recommended Level
Tension for Juniors
48-52 lbs for juniors. String at normal poly tensions.
Gauge Recommendation
17 (1.25mm) for best spin and control.
Overview
Signum Pro Firestorm is the ATP tour string that helped propel Matteo Berrettini into the top 10. Available in distinctive Metallic Gold, Firestorm offers the classic German polyester combination of spin, control, and durability that tour players demand. The balanced performance profile makes it suitable for aggressive baseliners who want to swing freely while maintaining placement accuracy.
Best For
- ✓ Powerful baseliners
- ✓ Players seeking tour-level performance
- ✓ Spin and control seekers
- ✓ Those wanting ATP-proven string
Not Ideal For
- ✗ Arm-sensitive players
- ✗ Beginners seeking comfort
- ✗ Players needing power assistance
Pros
- + ATP tour proven - Berrettini's choice
- + Excellent spin and control balance
- + Distinctive Metallic Gold color
- + Good durability
- + Outstanding value
Cons
- − Not arm-friendly
- − Firm feel may be harsh
- − Requires proper technique
Specifications
Type polyester
Construction Round co-polyester monofilament
Gauges 16, 17, 18
Colors Metallic Gold
Set Price $9-$12
Reel Price $90-$110
Used By
Hybrid Setup Ideas
- Natural gut mains with Firestorm crosses
- Wilson NXT crosses for comfort
Stringer Notes
Standard poly stringing. Metallic Gold finish - distinctive look. Static stiffness: 0.85 kg/mm.
Break-in Period
1-2 hours for full performance.
When to Replace
Every 15-20 hours or when spin response drops.
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